The present invention provides adjuvants, vaccines and related methods
that are useful in eliciting immune responses, particularly immune
responses against tumor antigens. We discovered that flagellin is capable
of inhibiting tolerance when it is administered in conjunction with a
tolerogenic antigen. This effect is likely mediated by the ability of
flagellin to induce IL-12 while keeping IL-10 levels low. Furthermore,
flagellin can be provided in an extended-releasing manner by using a
flagellin-expressing cell. Preferably, the flagellin-expressing cell is
treated such that it is no longer capable of replicating, yet retaining
the ability to express flagellin, such as by lethal irradiation.